This disclosure relates to polycarbonate compositions, methods of manufacture thereof and articles comprising the same.
Polycarbonate is an optically transparent polymeric resin that has high impact strength but a low modulus of elasticity. To increase the modulus of elasticity, glass fibers are usually added to the polycarbonate. This results in a loss of transparency as well as a reduction in the impact strength. When it is desired to change the color of glass filled polycarbonate composite, colorants are generally added to the composite. However, the addition of colorants generally reduces the impact properties of glass-reinforced polycarbonate.
In order to render a glass filled polycarbonate white or light in color, fillers such as titanium dioxide and zinc sulfide are often added to the polycarbonate resin. The addition of titanium dioxide to the polycarbonate however, causes a reduction in the size of the glass fibers, while the addition of the zinc sulfide causes a reduction in the molecular weight of the polycarbonate with a corresponding loss in impact strength. As a result of this decrease in impact strength, it is difficult to use white colored glass-filled polycarbonates in applications such as the exterior body panels of automobiles and electronic devices, computers and mobile phones, where the retention of impact strength is desirable.
It is therefore desirable to have a white colored glass-filled polycarbonate that has a high impact strength.